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We consider closed manifolds that admit a metric locally isometric to a product of symmetric planes. For such manifolds, we prove that the Euler characteristic is an obstruction to the existence of flat structures, confirming an old…

Geometric Topology · Mathematics 2009-05-23 Michelle Bucher , Tsachik Gelander

This study proposes a novel approach to extract topological properties, specifically the Euler characteristic, from input images using neural networks without relying on large pre-existing datasets but with a single geometric image.…

Machine Learning · Computer Science 2026-05-06 Gyunghun Yu , Seong Min Park , Han Gyu Yoon , Tae Jung Moon , Jun Woo Choi , Hee Young Kwon , Changyeon Won

The paper describes a natural splitting in the rational homology and homotopy of the spaces of long knots. This decomposition presumably arises from the cabling maps in the same way as a natural decomposition in the homology of loop spaces…

Algebraic Topology · Mathematics 2011-01-04 Victor Tourtchine

In this paper we develop in detail the geometric constructions that lead to many uniqueness results for the determination of polyhedral sets, typically scatterers, by a finite minimal number of measurements. We highlight how unique…

Analysis of PDEs · Mathematics 2023-10-10 Luca Rondi

We introduce and study a notion of cylinder coherator similar to the notion of Grothendieck coherator which define more flexible notion of weak infinity groupoids. We show that each such cylinder coherator produces a combinatorial…

Category Theory · Mathematics 2016-09-16 Simon Henry

We deal with a robust notion of weak normals for a wide class of irregular curves defined in Euclidean spaces of high dimension. Concerning polygonal curves, the discrete normals are built up through a Gram-Schmidt procedure applied to…

Differential Geometry · Mathematics 2021-05-11 Domenico Mucci , Alberto Saracco

Generating functions for the number of commuting m-tuples in the symmetric groups are obtained. We define a natural sequence of ``orbifold Euler characteristics'' for a finite group G acting on a manifold X. Our definition generalizes the…

Combinatorics · Mathematics 2007-05-23 Jim Bryan , Jason Fulman

We show that the discretized configuration space of $k$ points in the $n$-simplex is homotopy equivalent to a wedge of spheres of dimension $n-k+1$. This space is homeomorphic to the order complex of the poset of ordered partial partitions…

Geometric Topology · Mathematics 2011-09-30 Aaron Abrams , David Gay , Valerie Hower

This is the first part of a series of papers where we compute Euler characteristics, signatures, elliptic genera, and a number of other invariants of smooth manifolds that admit Riemannian metrics with positive sectional curvature and large…

Differential Geometry · Mathematics 2016-08-09 Manuel Amann , Lee Kennard

We characterise rigid graphs for cylindrical normed spaces $Z=X\oplus_\infty \mathbb{R}$ where $X$ is a finite dimensional real normed linear space and $Z$ is endowed with the product norm. In particular, we obtain purely combinatorial…

Metric Geometry · Mathematics 2023-05-16 Sean Dewar , Derek Kitson

Principal circle bundle over a PL polyhedron can be triangulated and thus obtains combinatorics. The triangulation is assembled from triangulated circle bundles over simplices. To every triangulated circle bundle over a simplex we associate…

Algebraic Topology · Mathematics 2016-08-30 Nikolai Mnev , Georgy Sharygin

We applied tensor network contraction algorithms to compute the hard-core lattice gas model, i.e., the enumeration of independent sets on grid graphs. We observed the influence of surface effect and parity effect on the enumeration (and…

Combinatorics · Mathematics 2025-08-11 Kai Liang

We consider spherically symmetric black holes with minimally coupled scalar fields and concentrate our attention on asymptotically flat self-gravitating configurations having the event horizons located at radii much smaller than $2m$. We…

General Relativity and Quantum Cosmology · Physics 2019-12-10 I. M. Potashov , Ju. V. Tchemarina , A. N. Tsirulev

We give a combinatorial characterization of generic frameworks that are minimally rigid under the additional constraint of maintaining symmetry with respect to a finite order rotation or a reflection. To establish these results we develop a…

Metric Geometry · Mathematics 2015-03-17 Justin Malestein , Louis Theran

Let G be a finite group and let M be a G-manifold. We introduce the concept of generalized orbifold invariants of M/G associated to an arbitrary group Gamma, an arbitrary Gamma-set, and an arbitrary covering space of a connected manifold…

Group Theory · Mathematics 2014-10-01 Hirotaka Tamanoi

We exhibit the first example of a knot in the three-sphere with a pair of minimal genus Seifert surfaces that can be distinguished using the sutured Floer homology of their complementary manifolds together with the Spin^c-grading. This…

Geometric Topology · Mathematics 2015-03-17 Irida Altman

Manifolds admitting positive sectional curvature are conjectured to have rigid homotopical structure and, in particular, comparatively small Euler charateristics. In this article, we obtain upper bounds for the Euler characteristic of a…

Differential Geometry · Mathematics 2014-07-22 Manuel Amann , Lee Kennard

Euler graphs are characterized by the simple criterion that degree of each node is even. By restricting on the cycle types yet additional intrinsic properties of Euler graphs are unveiled. For example, regularity higher than degree two is…

Combinatorics · Mathematics 2020-06-09 Suryaprakash Nagoji Rao

For the moduli spaces of Abelian differentials, the Euler characteristic is one of the most basic intrinsic topological invariants. We give a formula for the Euler characteristic that relies on intersection theory on the smooth…

Algebraic Geometry · Mathematics 2020-06-24 Matteo Costantini , Martin Möller , Jonathan Zachhuber

This paper establishes a metric framework for Spencer complexes based on the geometric theory of compatible pairs $(D,\lambda)$ in principal bundle constraint systems, solving fundamental technical problems in computing Spencer cohomology…

General Mathematics · Mathematics 2025-08-12 Dongzhe Zheng